There are many electronic devices and applications that implement current-mirroring to generate a resultant current having a magnitude proportional to a given first current. As an example, in preamplifier applications, an output bias current can be provided by a current digital-to-analog-converter (DAC) that varies widely in magnitude. Thus, current-mirroring can be implemented to substantially copy the output bias current, or to amplify the output bias current by a proportionality factor (e.g., greater than one).
A typical current-mirror configuration can include a pair of transistors that share a bias node. Thus, the pair of transistors are biased substantially the same. The current flow characteristic through each of the transistors can be based on a relative size of the transistors. Therefore, the relative size of the transistors can define a proportionality constant that substantially equally defines a relative magnitude of the current that flows through each of the transistors. Accordingly, device scaling can be implemented to amplify a given current in providing an output current from a current-mirror system.